On Hyprland the `top` layer renders above every window, including a real
fullscreen surface — so a browser video gone fullscreen sat *under* the
bar (BACKLOG item 30). Move the bar to `layer: bottom` in the generated
waybar.nix and all four whole-swap jsoncs (parity rule); the exclusive
zone still reserves its space in normal tiling, but a fullscreen window
now covers it. Rationale comment kept in waybar.nix; data jsoncs left
comment-free (they carry none).
Verified: V0 (nix flake check --no-build, green) + V1
(homeConfigurations.nomarchy.activationPackage builds; built
.config/waybar/config shows "layer": "bottom"). V3 queued in
HARDWARE-QUEUE (fullscreen covers bar + returns on exit; floating-overlap
trade-off).
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>